Fuel injection system for internal combustion engines



y 9, 1936. [K J. E. HESSELMAN 2,040,846

FUEL INJECTION SYSTEM FOR INTERNAL COMBUSTION ENGINES Filed Sept. 24,1932 @f /1 32 Zfa 39 x 18 29 i7 2% 4 O 0 30 62 429 3 4/ 37 38 A 23 22 j35 3/ H a /6 26 36W 37 fW W I 9 47 /0 INVENTOR 1 Ja 3. v W

A); ATTORNEY Patented May 19, 1936 FUEL INJECTION SYSTEM FOR INTERNALCOMBUSTION ENGINES Knut Jon'as Elias Application Hesselman,Saltsjo-torangen, Sweden September 24, 1932, Serial No. 634,710 InSweden April 22, 1929 13 Claims. (01. 299-1011) This applicationreplaces my copending applications Serial Nos. 439,602 and 439,603,filed March 28, 1930, and is a continuing application with respect to mycopending application Serial No. 538,756 filed May 20, 1931, and is tobe considered as relating back to said applications Se r-iai Nos.439,602 and 439,603 for all datesand rights incident to filing saidapplications and applications in foreign countries correspondingthereto, and as relating back, so far as herein continued, for all datesand rights incident to filing said application Serial No. 538,756 andapplications in foreign countries corresponding thereto.

The present invention relates primarily to fuel injection systems forinternal combustion engines and has particular reference to means forcontrolling the flow of fuel in injection systems of the solid injectiontype which inject to each cylinder of an engine a metered quantity offuel for each working stroke. More specifically the invention relatesto'valve structure particularly adapted to be associated with theinjection nozzles employed in such systems and to fuel injectorsconsisting of injector nozzle and discharge valve structure inassociated relation.

In solid injection fuel supply systems, numerous severe operatingconditions are imposed which must be met if the system is to operatesuccessfully and one of the most difiicult problems has been to provide.valve structure, particularly for the discharge valves of the system,which will operate successfully under the severe conditions imposedthereon. Valves suitable for this service must be of atype which willseat accurately over long periods of time, they must bev capable of freeand rapid action, they must be of a form such that they can be placedrelatively closely adjacent to the injection nozzle, and, 0 if they areto be of practical utility, the structure must be not only of acharacter eliminating very small orifices which are subject to cloggingdue to impurities in the fuel butmust also be of the simplest 'po'ssibleconstruction of a character .5 which permits ready disassembly of theparts for purposes of cleaning, repair or replacement. Also, if asatisfactorily practical structure is to be provided, it should'be of acharacter avoiding as far as possible the necessity for joints requiringpacking to prevent leakage of fuel.

The general object of the present invention is the provision of improvedapparatus including valve structure and injector structure which willsatisfactorily meet the numerous and relatively severe operatingrequirements for structures of this kind. ,The manner in which thegeneral object of the invention is attained and'the more specific natureof the invention, together with the advantages to be derived from itsuse, will be explained more fully in the ensuing description of thepreferred embodiments of the invention illustrated in the accompanyingdrawing forming a part of this specification.

In the drawing:

Fig. 1 is a view showing part of an engine cylinder having a fuel pumpand injection nozzle arrangement embodying the invention;

Fig. 2 is a section on a larger scale showing a discharge valvearrangement similar to the one shown in Fig. 1, and a Fig. 3 is a viewshowing an injection nozzle assembly incorporating the invention.

Turning now to the arrangement shown in Fig. 1, reference character l0indicates an engine cylinder in which is located a piston I l and whichis closed at the top by the cylinder head l2 which may or may not beseparate from the cylinder l0.

)A pump [3, for supplying fuel to combustion chamber 14, comprises apump body l5 having 'an integral laterally projecting arm l6 adapted toengage at I! and I8 the'walls of the bore I9 in the wall of cylinderIll. .The inner portion of bore I9 is of reduced diameter and provides ashoulder between which and a shoulder on arm I 6 there is situated thepacking rin'g 2|. Pump l3'may be retained in position by any suitablemeans, preferably some form of releasable clamp permitting ready removalof the pump such as is disclosed in- Patent No. 1,835,490 grant ed to meDecembe 8, 1931. a i I The pump illustrated is of the plunger type andcomprises a plunger 22 reciprocably mounted in a suitable bore in thepump" body l5 and adapted to draw fuel into pump chamber 23 on I theoutward stroke of the plunger and discharge fuel therefrom on theinwardstroke. Actuation of the pump plunger may be by any suitable knownmeans (not illustrated). Fuel discharged from' chamber 23 passes throughthe discharge channel 24 which is preferably bored through the pump bodyand which extends centrally through the pump arm l6. For reasons whichwill hereinafter be i more fully explained, the discharge channel ispreferably of relatively small'cross-sectional area so as to haveminimum volume and in order to facilitate manufacture, the portion 24aof the discharge channel may advantageously be formed by a tubulareleme'nt 25 seated in the bottom of a bore 26 of relatively largerdiameter which extends inwardly from the end of the arm I 6. Insofar asthe present invention is concerned, the element I 'may,be considered asan integral part of arm I6.

The outer end of arm I6 is threaded as at 21 and threaded over this end.of the arm is the annular clamping element 28 serving to releasably holdin position the injection nozzle 29 which has one or more orifices 3|!for spraying fuel into the combustion chamber |4. Nozzle 29 comprises atubular portion 3| and a base portion 32, the

latter portion having a lug 33 thereon adapted to enter a suitable notch34 in the end of the arm l6 to prevent turning of the injection nozzlerotationally from its proper position. The desirability of thisarrangement is to prevent displacement from proper position of theorifice ororifices 36 which may be angularly disposed with respect tothe longitudinal axis of the nozzle. The clamping element 28 mayadvantageously be provided with a sleeve portion 36 situated aroundnozzle 29 for protecting the nozzle against damage when the device isremoved from the engine cylinder. Thespecific details of the internalconstruction of the nozzle form no part of the present'invention and arenot illustrated herein. I have found, however, that one verysatisfactory type of nozzle to employ is that which is disclosed andclaimed in U. S. Patent No 1,888,082 granted to me November 15, 1932.

The outer portion of the bore 26 contains the valve mechanism andin theem en]: us-

. trated, the valve mechanism comprises two ball valves arrangedserially with respect to flow'of fuel to the injection nozzle.

Each of the ball valves comprises a tubular insert 36 located in thebore 26 and having a bore comprising spaced portions 31 and 38-ofreduceddiameter. The portion 31 of each insert provides a valve seat 39 engagedby a valve ball 40. Valve ball 4|! is seated by spring 4|, one end ofwhich contacts the valve ball and the other end (if which is guided inthe portion 36 of the bore. As will be observed from the figure, theguided end of the left hand spring 4| abuts against the end oftheadjacent or. right hand insert 36* and the guided end of the'spring4| in this latter insert abuts against an annular of further details ofthe invention. In the structure shown in this figure, 43 indicates anouter valve casingwhich corresponds to the arm |6,in

the arrangement shown in Fig- 1. Casing 43 is provided with a-bore 26with which the fuel discharge channel 24 communicates, and valve inserts36 are situated in bore 26 as in the embodimentshown in Fig.1. In thepresent embodiment, the'injection nozzle 29' is provided with arbaseportion 44 threaded to engage suitable threads 45 in the outer end ofthe bore 26. This arrangement is suitable for an injection nozzleadapted to project fuel axially of the nozzle so that the exact positionof the nozzle, rotationally,

i is immaterial;

Turning now more particularly to the details of the ball valves, whichin the present embodiment are identical with the device shown in Thewasher 42 I Fig. 1, it will be observed that the. end of each of springs4| which is in contact with a valve ball 40 is cut away inwardly so asto provide a surface 46 the contour of which is such as to give at leastone line of contact between the surface and the ball which is a truecircle normal to and' concentric with the axis of the bore andconsequently, concentric with respect-to the circle representing theline of contact between the valve ball and the valve seat 39. Surfaces46 are -preferably spherically .curved and have radii which are the sameasthe radii of. the balls. Also springs 4| are preferably made with endsurfaces normal to the axis of the springs and the springs are alsopreferably cut away inwardly to provide similar surfaces 46 at each endof each spring.

The portion 38 of the bore of each insert 36 isrelatively short axiallyof the insert and preferably has a length approximately equal to theaxial length of one turnof a valve spring 4|. The

. external diameter of each spring 4| is substantially the same as theexternal diameterof the valve ball 40 which it contacts and is alsosubstantially equal to the internal diameter of the portion 39 of thebore in which it is situated, this portion being just large enough topermit the valve ball to pass through it and providing a guide for.

holding the valve spring and the valve ball against any substantiallateral displacement.

As in the arrangement shown in Fig. 1, axial displacement of the springin the inner insert is prevented by abutment of one end of this springagainst the inner end of the outer insert, and

axial displacement of the spring in the outer in- ,sert is prevented byabutment of the end of this spring against an adjacent member, which inthe present instance is the base portion 44 of the injection nozzle. V 1

The arrangement shown in Fig. 3 illustrates an injection nozzle deviceadapted to be used in an injection system in which the fuel pumpislocated at a point remote from the engine cylinder. the embodimentillustrated, the body 41 of the device, which constitutes an outer valvecasing, comprises a cylindrical portion adapted to engage the walls ofbore l9 in the wall of cylinder l6 and having a'shoulder adapted toengage a packing ring 2| seating against a suitable shoulder in thebore- |9. The body or outer casing 41 is provided with a portion 48 ofreduced diameter around which there is loosely mounted the externallythreaded collar 49 which engages suitable threads 59 at the end of borel9. Collar 49 is provided witha head 6| adapted to be engaged by awrench or other suitable tool for screwing the .collar' into the bore.As will be evident from the figure, the

body or casing 41 will be seated in the bore by.

the abutment of the end of collar 49 against the external shoulder onthe casing 41.

A second collar 62 is pinned or otherwise suitably flxed on the portion46 of the casing, this collar constituting a retaining member forholding the loose collar 49 in its proper position when the device isremoved from the cylinder. A lug ,or other projection 53 on collar 52,adapted to engage a suitableslot 54in the cylinder, provides convenientmeans for fixing the casing v4! in a predetermined position of rotationin the bore l9.

The construction of the casing "with respect to the bore 26 therein forreceiving the valve inserts and also with respect to the manner in whichthe injection nozzle 29 is clamped to the end of the casing is similarto that previously detions adjacent the portions 31.

Fuel is supplied to the device through any suitable conduit such as thetubing indicated at 55, which is preferably detachably secured to thecasing 47 by means of any suitable known form of connection or unionconventionally represented at 56.

The operation of the above described arrangements as discharged valvesand also as so-called injection nozzle valves for fuel injection systemswill be largely obvious and requires no detailed explanation.

The advantages of the construction and the manner in which it meets theconditions existing in the systems of the type to which the inventionrelates will be briefly pointed out. It will be observed that theconstruction enables the valve balls to be placed very close to thepoint of fuel discharge from the injection nozzle. This results in thetrapping of, only a very small quantity of fuel between the nozzleoutlet and the nearest check valve. which is important for a number ofreasons; Fuel oil when subjected to high pressures is compressible to anappreciable extent and if the nearest check valve in the injectionsystem, which may be the pump discharge valve; is remote from theinjection nozzle, so that a relatively large quantity of fuel is in thedischarge conduit between the nozzle and the valve, the high pressuredeveloped in the engine cylinder on its working stroke may operate to socompress the fuel in the discharge line that combustion gases can enterthe bore of the injection nozzle and cause difiiculties due tocarbonization of fuel within the nozzle. Furthermore, if the arrangementis such that the nearest valve in the discharge line is remote from thenozzle, the meter-'- ing of the fuel with the degree of exactituderequired is rendered diflicult if not impossible. In

the arrangement shown the possibility of the above difiiculties isreduced to a minimum because of the extremely small volume of thedischarge'channel between the nozzle outlet and the to the nozzle,without imposing in the line of flow any small or needle-like orificeswhich are likely to clog with impurities. It is evident that the balltype of valveprovidesmuch less likelihood of difliculty due to cloggingthan doesa needle valve of equal flow capacity.

Although in solid injection systems, fuel is delivered at extremely highpressures, it has been found that with arrangements constructed inaccordance with the present invention no packing members are necessarybetween the. several separable elements in order to prevent leakage.

The abutting surfaces of the inserts contacting each other and the wallsof the outer valve casing form an effective seal preventing leakage offuel the embodimentsv illustrated is that which is used between theouter valve casing and the wall of the cylinder to prevent leakage ofcombustion gases and in some forms of construction even this packing maybe omitted, although it is generally preferable to employ it.

The particular spring arrangement used also contributes to improvedoperation of the device since the'cutting away of the spring ends incontact with the valve balls, coupled with the guiding of the springends in the valve inserts, insures exact centering of the valve ballswith respect to their seats. engagement of the balls with their seatsaround the entire circumferences thereof and minimizes This in turninsures simultaneous the possibility of wear of the seats or of theballs from their true contour. Byguiding the springs in the mannerillustrated, substantiallythe full length of each spring is free fromfrictional contact with any other element so that maximum effectivenessis obtained from a spring of given length and the possibility ofsluggish action or sticking of the springs due to a contacting guidesurface is eliminated. This is important because of the rapidity withwhich the valvesmust function when fuel is supplied therethrough to thecylinder of an engine operating at relatively high speed. The particulararrangement of the valve springs in the inserts also contributes towardminimizing the amount of fuel on the discharge side of the valves. Byusing cylindrical springs, shorter springs can be used for a givenspring load than if conical springs were used and the use of cylindricalsprings guided in the manner described permits the use of valve chamberson the dis-' charge side of the balls having minimum volume.

The arrangement according to the present inplacement of parts. Theconstruction involves no delicate adjustments and it is practicallyimpossible for the structure to be improperly assembled, particularlywhen, as is preferable, the

ends of the valve springs are made alike so that it is immaterial whichends of the springs contact the valve balls..

The several arrangements described above all relate to discharge orinjection valve devices and in these specific devices it is usuallydesirable on account of the high pressures involved to employ a seriesof valve balls rather than a single valve ball; In the specific examplesdescribed two valve balls have been employed but it will be evident thatthe number may be increased if desired, or if the pressures involved arerelatively low, a single valve ball may be sufficient.

The advantages to be derived from the use of certain of the novelfeatures of the construction are obviously not confined to dischargevalve devices but mayalso be employed in connection with inletvalves. Byway of illustration of this latter use, I have shown in Fig. 1 a valvearrangement similar to that previously described as employed for theinlet valve of the pump Hi. In this pump fuel is admitted to the body ofthe pump through a suitable opening 57 and passes to the inlet chamber58 within the body of the pump. The pump body is recessed at 59 toreceive a valve Insert is retained in position by the annular. collar orplug. 60 threaded into the pump body and the valve purposes, one valveball is ordinarily suflicient. Removal of the insert it isadvantageously facilitated by the provision of a suitable opening in theouter portion of thevaive body through which the collar and insert 36may be removed, this opening being normally closed by plug 62. i

From the foregoing description it will be evident that the invention isapplicable to many different specific applications and that the form andarrangement of the parts in different installations may varywidely'without departing from the scope of the invention. The inventionalso may be employed with any suitable mechaism for providing a properlymetered and timed supply of fuel.

What I claim is:

1. In apparatus of the character set forth, a

valve comprising an integral casing having a bore therein having areduced portion providing a valve seat, a cylindrical helical springinsaid bore, and

a spherical valve ball in said bore between said spring and said valveseat, said spring urging said ball against said seat, said spring havinga plurality of turns, said bore adjacent one or a relatively few turnsof said spring remote from said seat being of a diameter substantiallyequal to the external diameter of the spring to guide the same, saidbore being of greater diameter adjacent a relatively greater. number ofturns between the guided portion and the valve member, and saidvalveball being of substantially the same diameter as the externaldiameter of the spring so as to barely pass through the bore at theplace of guiding the spring.

2. In apparatus of the character set forth, a

valve comprising an integral casing having a bore therein having areduced portion providing a valve seat, a spherical valve ball adaptedto engage said, seat and a cylindrical helical spring engaging said ballat the end of the spring for urging said ball against said seat andhaving said end cut away inwardly to provide a spherically curvedsurface of contact with the ball, said surface being concentric aboutthe axis of the spring a and having the same radius as that of the ball,

' valve comprising an integral valve casing having a bore therethrough,said bore having axially spaced portions of reduced diameter and one ofsaid portions providing a valve seat, a spherical valve ball adapted toenga e said seat and a cylindrical helical spring for urging said valvetoward said seat, said spring having an external diameter substantiallyequal to the diameter of the rea duced portion of the bore remote fromthe'seat,

the length of the last mentioned portion of the bore being approximatelyequal to the axial length of. one turn of thespring, the turn of thespring remote from said seat being situated in said last mentionedportion of the bore and guided thereby, the entire bore between saidseat and said last mentioned portion being of greater diameter than thespring, and said valve ball being of substantially the same diameter asthe external diameter of the spring so as to barely pass through thebore at the place of guiding the spring.

4. In apparatus of the character set forth, a

valve insert comprising an inner casing having a smooth cylindricalouter surface and adapted a to seat in a cylindrical recess within anouter casing, said inner casing having a bore there-* member beingformed to provide contact surface 1 betweenthe spring and the valvemember symmetrical with respect to the common longitudinal axis of thespring and the casing and the end ofthe spring remote from the'valvemember being formed with a surface normal to said aids, the length ofthe portion of the bore of reduced diameter remote from the valve seatbeing situated in the last-mentioned portion of the bore and guidedthereby, said spring being,

slidably removable from said inner casing .through the last-mentionedportion of the bore and the end of the spring remote from the valvemember being adapted to be retained in position by a member held withinthe outer valve casing and abutting against-the end of the inner valvecasing, the entire bore between said seat and the portion of reduceddiameter remote from the valve seat being of greater diameter than thespring and said valve member being of'sub- ,stantially the same diameteras the external diameter of the spring so as to barely pass through thebore at the place guidingthe spring.

5. In fuel injection apparatus, a casing adapted to be removably securedin a suitable bore communicating with the combustion chamber of anengine, said casing having a channel there-- channel and incommunication therewith and including spring-loaded valve means, and aninjection nozzle having an open channel therethrough removably securedto the end of said casing adjacent to one of said inserts, said valvemeans being arranged to check the fuel supply to-said nozzle, and meansfor attaching an oil 'supplyline to said casing for delivery of oil tothe first mentioned channel.

6. In fuel injection apparatus, a casing adapted to be removably securedin a suitable bore communicating withthe combustion chamber of anengine, said casing having a channel therethrough for flow of liquidfuel, said channel having a portion of enlarged diameter at one end, aplurality of tubular inserts removably secured in said portion, saidinserts providing a channel therethrough coaxial with said first-namedchannel and in communication therewith, springloaded valves in saidinserts, an injection nozzle having a base portion adapted to be clampedto the end of said casing adjacent to said inserfs and a tubular portionadapted to extend coaxially of said channel when the nozzle is inposition, means for removably clamping said base portion to the end ofsaid casing, said means tubular portion of said nozzle to protect thesame, and means for attaching an oil supply line to said casing fordelivery of oil to the first named channel. a

'7. In fuel injection apparatus, a casing adapted to be removablysecured in a suitable bore in the cylinder structure of an engine andcommunicating with the combustion chamber of the cylinder, said casinghaving a passage therethrough for fiow of fuel, said passage having aportion of enlarged diameter at one end of the casing, a tubular insertremovably mounted in said portion of said passage, said insert having aspring-loaded valve therein and having a passage therethrough incommunication with the first-mentioned passage, a fuel injection nozzleadapted to be clamped to said one end of said casing, said nozzle havinga discharge orifice angularly disposed with respect to the axis of saidcasing, means for clamping the nozzle to the casing, means for fixingthe nozzle rotationally with respect to the casing, means for fixing thecasing rotationally with respect to the engine cylinder structure, andmeans for attaching an oil supply line to said casing for delivery ofoil to the first mentioned passage.

8. In fuel injection apparatus, a casing adapted to be removably seatedin a suitable bore in the engine cylinder structure and communieatingwith the combustion chamber of the cylinder, said casing having apassage therethrough for flow of fuel, said passage having a portion ofenlarged diameter at one end of'the casing, a tubular valve insert insaid portion of enlarged diameter, a spring-loaded. valve in saidinsert, a fuel injection nozzle removably clamped to the end of saidcasing adjacent said insert and acting to retain said insert in positionin the casing, said nozzle having adischarge orifice an-, gularlydisposed with respect to the axis of said casing, means for fixing thenozzle rotationally with respect to the casing, means for fixing thecasing rotationally with respect to said cylinder structure, meanscooperating with said casing and said cylinder structure for removablyclamping said casing in said bore and means for attaching an oil supplyline to said casing for delivery of oil to said passage.

9. In. fuel injection apparatus, a casing having a portion adapted toengage the wall of a suit able bore in an engine cylinder structurecommunicating with the combustion chamber of the cylinder and portionsof reduced diameter at either side of the first-mentioned portion, achan nel for flow of fuel through said casing, a valve insert having aspring-loaded valve therein located in said channel, a. fuel injectionnozzle removably clamped to one of said portions of, re-

duced diameter at the end of the casing adjacent said valveinsert, saidnozzle being rotationallyed to seat in a suitable opening communicatingwith the combustion chamber of an engine, said lar inserts slidablymounted in said bore, each of said inserts having a bore therethroughcomprising a portion of reduced diameter providing a valve seat, thebores in said inserts being in communication, a. plurality of valvemembers each having a spherically curved surface adapted to engage oneof said seats, a plurality of springs each having an end engaging one ofsaid valve members to seat it, means comprising a fuel injection nozzledetachably secured to said casing for retaining said outer insert andits associated ed to seat in a suitable opening, said casing hav-- ing abore communicating with the combustion chamber of an engine therein, aplurality of tubular inserts slidably mounted in said bore, each of saidinserts having a bore there through comprising spaced portions ofreduced diameter, one of said portions providing a valve seat and theother of said portions providing a guide, the bores in said insertsbeing in communication, a plurality of valve members each having aspherically curved surface adapted to engage one of said seats, aplurality of springs, each of said springs engaging at its one end oneof said guides and at its opposite end engaging one of said valvemembers, the outer insert acting to retain the adjacent insert and itsassociated spring in position, means comprising a fuel injection nozzledetachably secured to the end of said casing for retaining said outerinsert and its associated spring in position, there being a channel foradmitting oil through said casing to the bore of the innermost insertinwardly of the valve seat therein and a channel for conducting oil fromthe bore of the outermost insert to said injection nozzle, and means forattaching an oil supply line to said casing for delivery of oil to thefirst mentioned channel.

12. In fuel injection apparatus, a casing adapted to seat in a suitableopening communicating with the combustion chamber of an engine, saidcasing having a bore therein, said bore having a shoulder therein, apluralityof tubular inserts slidably mounted in axially abuttingrelation in said bore, each of said inserts having a bore therethroughcomprising spaced portions of reduced diameter, one of said portionsproviding a valve seat and the other of said portions providing. aguide, the bores in said inserts being in communication and theinnermost insert seating against said shoulder, a plurality of valvemembers each having a spherically curved surface adapted to engage oneof said seats, a plurality of springs, each of said springs engaging atits one end one of said guides and at its opposite end engaging one ofsaid valve members, the outer insert acting to retain the adjacentinsert and its associated spring'in position, a fuel injection nozzlehaving a recessed base portion, an annular member adapted to engage theend of the bore in said casing and a recess in said base portion forcentering the nozzle with respect to the bore, a memher for detachablysecuring the injection nozzle to the end of, said casing, said nozzleand said members constituting means for retaining said outer insert andits associated spring in position,

a ing having a bore therein, a' plurality of tubuthere being a channelfor admitting oil through said casing to the bore of the innermostinsert inwardly orthe valve seat therein .and said annular memberproviding a channel for conducting oil from the bore oi. the outermostinsert to said injection nozzle, and means for attaching an oil supplyline to said casing tordelivery of oil to the first mentioned channel.

13. In fuel injection apparatus, a casing adapted to seat in a suitableopening communicating with the combustion chamber of an engine, saidcasing having a cylindrical bore therein at its outer ,end, said borehaving an inlet for liquid fuel at its inner end, a plurality oi tubularvalve inserts slidably mounted in said bore, each of said insertscontaining a spherically curved valve and a spring for seating thevalve, the outer insert casing for fixing the casing rotationallywithirespect to the engine cylinder, and means for attaching an oil supplyline to said casing for delivery of oil'to said inlet. 7

" KNU'I'JONAS msnnssmmn.

